T suppressor cells and suppressor factor which act at the efferent stage of the contact sensitivity skin reaction: their production by mice injected with water-soluble, chemically reactive derivatives of oxazolone and picryl chloride.

The water soluble, chemically reactive thioglycollic acid thioether derivatives of oxazolone and picryl chloride were synthesized and tested for their ability to prevent the development of contact sensitivity. Mice given two injections of these agents showed partial or complete unresponsiveness when subsequently sensitized and challenged with oxazolone and picryl chloride, respectively. This unresponsiveness was associated with T suppressor cells, Ts-eff(cs), which blocked the efferent stage of the contact sensitivity reaction, i.e. the passive transfer of contact sensitivity. These Ts-eff(cs) were entirely specific when tested with the corresponding antigen. However, the suppression which they caused had a non-specific final common pathway. Cell from mice injected with the oxazolone and picryl thioethers and painted with the corresponding contact sensitizer produced a suppressor factor in vitro. This factor specifically blocked passive transfer by immune cells incubated in it. It also armed macrophages which then caused suppression. These macrophages were most effective when injected intraperitoneally. The suppressor factor had a molecular weight between 30,000 and 100,000 and the alpha-oxazolone factor was absorbed by oxazolone-albumin Sepharose and could be eluted with oxazolone-epsilon-aminocaproic acid. It was also absorbed by concanavalin-A-sepharose and could be eluted with alpha-methylmannoside. It is proposed that the ability of water soluble, chemically reactive haptenes to evoke a Ts-eff(cs) population may be relevent to the rarity of severe drug reactions following the injection of chemically reactive drugs.